So that whenever this failed:
expect(response).to have_gitlab_http_status(200)
We see what's the response there. Here's an example:
```
1) API::Settings Settings PUT /application/settings custom repository storage type set in the config updates application settings
Failure/Error: expect(response).to have_gitlab_http_status(200)
expected the response to have status code 200 but it was 400. The response was: {"error":"password_authentication_enabled, signin_enabled are mutually exclusive"}
```
